Fix document retention and helper retry regressions

Keep failed cursor trials and native recapture anchored to the original document, and restore the requested cached root before LRU eviction. Base braille retry resets on established connection time rather than stalled startup. Poll private AT-SPI daemon ownership without triggering service activation and clean up partial startup failures. Add focused regressions and update browser testing notes.

internal/app/braille_session.go

@@ -45,8 +45,13 @@ func (worker *brailleWorker) run(ctx context.Context, done chan struct{}) {
 	backoff := time.Duration(0)
 	lastError := ""
 	for ctx.Err() == nil {
-		started := time.Now()
-		err := worker.session(ctx)
+		connectedFor, err := worker.session(ctx)
+		// Only a healthy, established connection resets retry history. Waiting
+		// for the helper's ready message can itself take several minutes.
+		if connectedFor > 10*time.Second {
+			backoff = 0
+			lastError = ""
+		}
 		if err != nil && ctx.Err() == nil {
 			if err.Error() != lastError {
 				worker.logger.Warn("braille helper disconnected", "error", err)
@@ -55,12 +60,6 @@ func (worker *brailleWorker) run(ctx context.Context, done chan struct{}) {
 				worker.logger.Debug("braille helper still unavailable", "error", err)
 			}
 		}
-		// A session that stayed up a while was a real connection; do not
-		// keep growing the delay after it ends.
-		if time.Since(started) > 10*time.Second {
-			backoff = 0
-			lastError = ""
-		}
 		backoff = nextBrailleBackoff(backoff)
 		select {
 		case <-ctx.Done():
@@ -70,23 +69,31 @@ func (worker *brailleWorker) run(ctx context.Context, done chan struct{}) {
 	}
 }
 
-func (worker *brailleWorker) session(ctx context.Context) (result error) {
+// connectedFor excludes startup waits so the supervisor can distinguish an
+// established connection from a slow failed handshake.
+func (worker *brailleWorker) session(ctx context.Context) (connectedFor time.Duration, result error) {
+	var connectedAt time.Time
+	defer func() {
+		if !connectedAt.IsZero() {
+			connectedFor = time.Since(connectedAt)
+		}
+	}()
 	defer func() { worker.mu.Lock(); worker.connected = false; worker.mu.Unlock() }()
 	childCtx, cancel := context.WithCancel(ctx)
 	defer cancel()
 	command := exec.CommandContext(childCtx, worker.path, "--client")
 	stdin, err := command.StdinPipe()
 	if err != nil {
-		return err
+		return 0, err
 	}
 	stdout, err := command.StdoutPipe()
 	if err != nil {
-		return err
+		return 0, err
 	}
 	var stderr bytes.Buffer
 	command.Stderr = &stderr
 	if err := command.Start(); err != nil {
-		return err
+		return 0, err
 	}
 	waitDone := make(chan struct{})
 	var waitErr error
@@ -154,17 +161,18 @@ readyWait:
 		select {
 		case err := <-ready:
 			if err != nil {
-				return err
+				return 0, err
 			}
 			break readyWait
 		case <-notice.C:
 			worker.logger.Info("waiting for braille display")
 		case <-giveUpTimer.C:
-			return errors.New("braille helper connection timed out")
+			return 0, errors.New("braille helper connection timed out")
 		case <-ctx.Done():
-			return nil
+			return 0, nil
 		}
 	}
+	connectedAt = time.Now()
 	worker.logger.Info("braille helper connected")
 	worker.mu.Lock()
 	worker.connected = true
@@ -198,15 +206,15 @@ readyWait:
 	for {
 		select {
 		case <-waitDone:
-			return waitErr
+			return 0, waitErr
 		case err := <-writeError:
-			return err
+			return 0, err
 		case err := <-readErrors:
-			return err
+			return 0, err
 		case event := <-routes:
 			worker.route(childCtx, event)
 		case <-ctx.Done():
-			return nil
+			return 0, nil
 		}
 	}
 }